Abstract

The optical characteristics of both paraxial and nonparaxial design kinoforms are reviewed. A comparison of the aberration properties of each design indicates that the choice of design depends on the application. For collimation or collection at large apertures, the nonparaxial design is necessary. In spite of the presence of spherical aberration, however, in some cases the paraxial design is preferred. As an example of the potential usefulness of the paraxial design, a flat-field planar kinoform landscape lens free from third-order coma and astigmatism is designed. Due to the inherent large amount of chromatic aberration in diffractive optics, this lens is limited to monochromatic operation, but the restrictions on aperture and field angle from the remaining monochromatic aberrations are approximately the same as for a conventional refractive lens. Theoretical predictions are compared to experimental results from the two different types of kinoform, with particular emphasis on diffraction efficiency and image quality.

© 1988 Optical Society of America